diff --git a/lib/model/address.js b/lib/model/address.js
index ef042d0..c8ffa38 100644
--- a/lib/model/address.js
+++ b/lib/model/address.js
@@ -2,16 +2,23 @@
 
 var Bitcore = require('bitcore');
 
-function Address(opts) {
-  opts = opts || {};
-
-  this.createdOn = Math.floor(Date.now() / 1000);
-  this.address = opts.address;
-  this.path = opts.path;
-  this.publicKeys = opts.publicKeys;
+function Address() {
+  this.version = '1.0.0';
 };
 
-Address.fromObj = function (obj) {
+Address.create = function(opts) {
+  opts = opts || {};
+
+  var x = new Address();
+
+  x.createdOn = Math.floor(Date.now() / 1000);
+  x.address = opts.address;
+  x.path = opts.path;
+  x.publicKeys = opts.publicKeys;
+  return x;
+};
+
+Address.fromObj = function(obj) {
   var x = new Address();
 
   x.createdOn = obj.createdOn;
@@ -28,7 +35,7 @@ Address.fromObj = function (obj) {
  * @param {number} threshold - amount of required signatures to spend the output
  * @return {Script}
  */
-Address.prototype.getScriptPubKey = function (threshold) {
+Address.prototype.getScriptPubKey = function(threshold) {
   return Bitcore.Script.buildMultisigOut(this.publicKeys, threshold).toScriptHashOut();
 };
 
diff --git a/lib/model/addressmanager.js b/lib/model/addressmanager.js
index 6786016..a2e6305 100644
--- a/lib/model/addressmanager.js
+++ b/lib/model/addressmanager.js
@@ -1,24 +1,34 @@
 var _ = require('lodash');
 var HDPath = require('../hdpath');
 
-function AddressManager(opts) {
-  this.receiveAddressIndex = 0;
-  this.changeAddressIndex = 0;
-  this.copayerIndex = (opts && _.isNumber(opts.copayerIndex)) ? opts.copayerIndex : HDPath.SHARED_INDEX;
+function AddressManager() {
+  this.version = '1.0.0';
+};
+
+AddressManager.create = function(opts) {
+  opts = opts || {};
+
+  var x = new AddressManager();
+
+  x.receiveAddressIndex = 0;
+  x.changeAddressIndex = 0;
+  x.copayerIndex = (opts && _.isNumber(opts.copayerIndex)) ? opts.copayerIndex : HDPath.SHARED_INDEX;
+
+  return x;
 };
 
 
-AddressManager.fromObj = function (obj) {
+AddressManager.fromObj = function(obj) {
   var x = new AddressManager();
 
-  x.receiveAddressIndex = obj.receiveAddressIndex; 
+  x.receiveAddressIndex = obj.receiveAddressIndex;
   x.changeAddressIndex = obj.changeAddressIndex;
   x.copayerIndex = obj.copayerIndex;
 
   return x;
 };
 
-AddressManager.prototype._incrementIndex = function (isChange) {
+AddressManager.prototype._incrementIndex = function(isChange) {
   if (isChange) {
     this.changeAddressIndex++;
   } else {
@@ -26,11 +36,11 @@ AddressManager.prototype._incrementIndex = function (isChange) {
   }
 };
 
-AddressManager.prototype.getCurrentAddressPath = function (isChange) {
-  return HDPath.Branch(isChange  ? this.changeAddressIndex : this.receiveAddressIndex, isChange, this.copayerIndex);
+AddressManager.prototype.getCurrentAddressPath = function(isChange) {
+  return HDPath.Branch(isChange ? this.changeAddressIndex : this.receiveAddressIndex, isChange, this.copayerIndex);
 };
 
-AddressManager.prototype.getNewAddressPath = function (isChange) {
+AddressManager.prototype.getNewAddressPath = function(isChange) {
   var ret = this.getCurrentAddressPath(isChange);
   this._incrementIndex(isChange);
   return ret;
diff --git a/lib/model/copayer.js b/lib/model/copayer.js
index 4e9ce77..d9cfc31 100644
--- a/lib/model/copayer.js
+++ b/lib/model/copayer.js
@@ -11,11 +11,10 @@ var AddressManager = require('./addressmanager');
 var Utils = require('../walletutils');
 
 
-var VERSION = '1.0.0';
 var MESSAGE_SIGNING_PATH = "m/1/0";
 
 function Copayer() {
-  this.version = VERSION;
+  this.version = '1.0.0';
 };
 
 Copayer.create = function(opts) {
@@ -32,7 +31,7 @@ Copayer.create = function(opts) {
   x.name = opts.name;
   x.xPubKeySignature = opts.xPubKeySignature; // So third parties can check independently
   x.signingPubKey = x.getSigningPubKey();
-  x.addressManager = new AddressManager({
+  x.addressManager = AddressManager.create({
     copayerIndex: opts.copayerIndex
   });
 
diff --git a/lib/model/notification.js b/lib/model/notification.js
index 0b51988..07b621f 100644
--- a/lib/model/notification.js
+++ b/lib/model/notification.js
@@ -1,5 +1,3 @@
-
-
 var Uuid = require('uuid');
 
 /*
@@ -20,25 +18,33 @@ var Uuid = require('uuid');
  * { amount: 'xxx', address: 'xxx'}
  * { txProposalId: 'xxx', copayerId: 'xxx' }
  *
- * Data is meant to provide only the needed information 
- * to notify the user 
+ * Data is meant to provide only the needed information
+ * to notify the user
  *
  */
+function Notification() {
+  this.version = '1.0.0';
+};
 
-function Notification(opts) {
+Notification.create = function(opts) {
   opts = opts || {};
 
+  var x = new Notification();
+
   var now = Date.now();
-  this.createdOn = Math.floor(now / 1000);
-  this.id = ('00000000000000' + now).slice(-14) + ('0000' + opts.ticker||0).slice(-4) ;
-  this.type = opts.type || 'general';
-  this.data = opts.data;
+  x.createdOn = Math.floor(now / 1000);
+  x.id = ('00000000000000' + now).slice(-14) + ('0000' + opts.ticker || 0).slice(-4);
+  x.type = opts.type || 'general';
+  x.data = opts.data;
+
+  return x;
 };
 
 Notification.fromObj = function(obj) {
-  var x= new Notification();
+  var x = new Notification();
 
   x.createdOn = obj.createdOn;
+  x.id = obj.id;
   x.type = obj.type,
   x.data = obj.data;
 
diff --git a/lib/model/txproposal.js b/lib/model/txproposal.js
index eac5480..fb04a9b 100644
--- a/lib/model/txproposal.js
+++ b/lib/model/txproposal.js
@@ -7,28 +7,32 @@ var Address = Bitcore.Address;
 
 var TxProposalAction = require('./txproposalaction');
 
-var VERSION = '1.0.0';
+function TxProposal() {
+  this.version = '1.0.0';
+};
 
-function TxProposal(opts) {
+TxProposal.create = function(opts) {
   opts = opts || {};
 
-  this.version = VERSION;
+  var x = new TxProposal();
 
   var now = Date.now();
-  this.createdOn = Math.floor(now / 1000);
-  this.id = ('00000000000000' + now).slice(-14) + Uuid.v4();
-  this.creatorId = opts.creatorId;
-  this.toAddress = opts.toAddress;
-  this.amount = opts.amount;
-  this.message = opts.message;
-  this.proposalSignature = opts.proposalSignature;
-  this.changeAddress = opts.changeAddress;
-  this.inputs = opts.inputs;
-  this.inputPaths = opts.inputPaths;
-  this.requiredSignatures = opts.requiredSignatures;
-  this.requiredRejections = opts.requiredRejections;
-  this.status = 'pending';
-  this.actions = {};
+  x.createdOn = Math.floor(now / 1000);
+  x.id = ('00000000000000' + now).slice(-14) + Uuid.v4();
+  x.creatorId = opts.creatorId;
+  x.toAddress = opts.toAddress;
+  x.amount = opts.amount;
+  x.message = opts.message;
+  x.proposalSignature = opts.proposalSignature;
+  x.changeAddress = opts.changeAddress;
+  x.inputs = [];
+  x.inputPaths = [];
+  x.requiredSignatures = opts.requiredSignatures;
+  x.requiredRejections = opts.requiredRejections;
+  x.status = 'pending';
+  x.actions = {};
+
+  return x;
 };
 
 TxProposal.fromObj = function(obj) {
@@ -51,7 +55,7 @@ TxProposal.fromObj = function(obj) {
   x.inputPaths = obj.inputPaths;
   x.actions = obj.actions;
   _.each(x.actions, function(action, copayerId) {
-    x.actions[copayerId] = new TxProposalAction(action);
+    x.actions[copayerId] = TxProposalAction.fromObj(action);
   });
 
   return x;
@@ -136,7 +140,7 @@ TxProposal.prototype.getActionBy = function(copayerId) {
 };
 
 TxProposal.prototype.addAction = function(copayerId, type, comment, signatures, xpub) {
-  var action = new TxProposalAction({
+  var action = TxProposalAction.create({
     copayerId: copayerId,
     type: type,
     signatures: signatures,
diff --git a/lib/model/txproposalaction.js b/lib/model/txproposalaction.js
index a215657..8e6dd31 100644
--- a/lib/model/txproposalaction.js
+++ b/lib/model/txproposalaction.js
@@ -1,14 +1,22 @@
 'use strict';
 
-function TxProposalAction(opts) {
+function TxProposalAction() {
+  this.version = '1.0.0';
+};
+
+TxProposalAction.create = function(opts) {
   opts = opts || {};
 
-  this.createdOn = Math.floor(Date.now() / 1000);
-  this.copayerId = opts.copayerId;
-  this.type = opts.type || (opts.signatures ? 'accept' : 'reject');
-  this.signatures = opts.signatures;
-  this.xpub = opts.xpub;
-  this.comment = opts.comment;
+  var x = new TxProposalAction();
+
+  x.createdOn = Math.floor(Date.now() / 1000);
+  x.copayerId = opts.copayerId;
+  x.type = opts.type || (opts.signatures ? 'accept' : 'reject');
+  x.signatures = opts.signatures;
+  x.xpub = opts.xpub;
+  x.comment = opts.comment;
+
+  return x;
 };
 
 TxProposalAction.fromObj = function(obj) {
diff --git a/lib/model/wallet.js b/lib/model/wallet.js
index 634312a..6c20903 100644
--- a/lib/model/wallet.js
+++ b/lib/model/wallet.js
@@ -10,11 +10,8 @@ var Copayer = require('./copayer');
 var AddressManager = require('./addressmanager');
 var WalletUtils = require('../walletutils');
 
-var VERSION = '1.0.0';
-
-
 function Wallet() {
-  this.version = VERSION;
+  this.version = '1.0.0';
 };
 
 Wallet.create = function(opts) {
@@ -33,7 +30,7 @@ Wallet.create = function(opts) {
   x.copayers = [];
   x.pubKey = opts.pubKey;
   x.network = opts.network;
-  x.addressManager = new AddressManager();
+  x.addressManager = AddressManager.create();
 
   return x;
 };
@@ -125,7 +122,7 @@ Wallet.prototype.createAddress = function(isChange) {
   $.checkState(this.isComplete());
 
   var path = this.addressManager.getNewAddressPath(isChange);
-  return new Address(WalletUtils.deriveAddress(this.publicKeyRing, path, this.m, this.network));
+  return Address.create(WalletUtils.deriveAddress(this.publicKeyRing, path, this.m, this.network));
 };
 
 
diff --git a/lib/server.js b/lib/server.js
index 18d61f1..71f77dc 100644
--- a/lib/server.js
+++ b/lib/server.js
@@ -169,7 +169,7 @@ CopayServer.prototype._notify = function(type, data) {
   var walletId = self.walletId || data.walletId;
   $.checkState(walletId);
 
-  var n = new Notification({
+  var n = Notification.create({
     type: type,
     data: data,
     ticker: this.notifyTicker++,
@@ -496,7 +496,7 @@ CopayServer.prototype.createTx = function(opts, cb) {
           locked: true
         });
 
-        var txp = new TxProposal({
+        var txp = TxProposal.create({
           creatorId: self.copayerId,
           toAddress: opts.toAddress,
           amount: opts.amount,
diff --git a/test/addressmanager.js b/test/addressmanager.js
index 3f0a7fb..d496a87 100644
--- a/test/addressmanager.js
+++ b/test/addressmanager.js
@@ -10,7 +10,7 @@ var AddressManager = require('../lib/model/addressmanager');
 describe('AddressManager', function() {
   describe('#getCurrentAddressPath', function() {
     it('should return a valid BIP32 path for given index', function() {
-      var am = new AddressManager({
+      var am = AddressManager.create({
         copayerIndex: 4
       });
       am.getCurrentAddressPath(false).should.equal('m/4/0/0');
@@ -19,14 +19,14 @@ describe('AddressManager', function() {
   });
   describe('#getCurrentAddressPath', function() {
     it('should return a valid BIP32 path for defaut Index', function() {
-      var am = new AddressManager();
+      var am = AddressManager.create();
       am.getCurrentAddressPath(false).should.equal('m/2147483647/0/0');
       am.getCurrentAddressPath(true).should.equal('m/2147483647/1/0');
     });
   });
   describe('#getNewAddressPath', function() {
     it('should return a new valid BIP32 path for given index', function() {
-      var am = new AddressManager({
+      var am = AddressManager.create({
         copayerIndex: 2
       });
       am.getNewAddressPath(false).should.equal('m/2/0/0');